/*
  SD card basic file example

 This example shows how to create and destroy an SD card file
 The circuit:
 * SD card attached to SPI bus as follows:
 ** UNO:  MOSI - pin 11, MISO - pin 12, CLK - pin 13, CS - pin 4 (CS pin can be
 changed) and pin #10 (SS) must be an output
 ** Mega:  MOSI - pin 51, MISO - pin 50, CLK - pin 52, CS - pin 4 (CS pin can be
 changed) and pin #52 (SS) must be an output
 ** Leonardo: Connect to hardware SPI via the ICSP header

 created   Nov 2010
 by David A. Mellis
 modified 9 Apr 2012
 by Tom Igoe
 modified 16 Aug 2017  by Lambor Fang

 This example code is in the public domain.

 */
#include <SD.h>

File myFile;

// change this to match your SD shield or module;
//     Arduino Ethernet shield: pin 4
//     Adafruit SD shields and modules: pin 10
//     Sparkfun SD shield: pin 8
const int chipSelect = 43;

void setup() {
    SerialUSB.print( "Initializing SD card..." );
    // On the Ethernet Shield, CS is pin 4. It's set as an output by default.
    // Note that even if it's not used as the CS pin, the hardware SS pin
    // (10 on most Arduino boards, 53 on the Mega) must be left as an output
    // or the SD library functions will not work.
    pinMode( SS, OUTPUT );

    if ( !SD.begin( chipSelect ) ) {
        SerialUSB.println( "initialization failed!" );
        return;
    }
    SerialUSB.println( "initialization done." );

    if ( SD.exists( "example.txt" ) ) {
        SerialUSB.println( "example.txt exists." );
    }
    else {
        SerialUSB.println( "example.txt doesn't exist." );
    }

    // open a new file and immediately close it:
    SerialUSB.println( "Creating example.txt..." );
    myFile = SD.open( "example.txt", FILE_WRITE );
    myFile.close();

    // Check to see if the file exists:
    if ( SD.exists( "example.txt" ) ) {
        SerialUSB.println( "example.txt exists." );
    }
    else {
        SerialUSB.println( "example.txt doesn't exist." );
    }

    // delete the file:
    SerialUSB.println( "Removing example.txt..." );
    SD.remove( "example.txt" );

    if ( SD.exists( "example.txt" ) ) {
        SerialUSB.println( "example.txt exists." );
    }
    else {
        SerialUSB.println( "example.txt doesn't exist." );
    }
}

void loop() {
    // nothing happens after setup finishes.
}
